Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 15, 2014
Previous Article Next Article

Optimized cross-slot microdevices for homogeneous extension

Author affiliations

Abstract

Microfluidic cross-slot devices can generate wide regions of vorticity-free strong extensional flow near the stagnation point, resulting in large extensional deformation and orientation of the microstructure of complex fluids, with possible applications in extensional rheometry and hydrodynamic stretching of single cells or molecules. Standard cross-slot devices, with sharp or rounded corners, generate a flow field with a non-homogeneous extension rate that peaks at the stagnation point, but decays significantly with distance from the stagnation point. To circumvent this limitation, an optimized shape cross-slot extensional rheometer (OSCER) was designed numerically and shown to generate constant extension rate over a wide region of the in- and out-flowing symmetry planes [Haward et al., Phys. Rev. Lett., 2012, 109, 128301]. Since the OSCER device was based on a 2D flow approximation, the practical implementation requires a large aspect ratio, which cannot be reproduced by standard soft-lithography techniques. Here, we propose a set of new designs for optimized cross-slot geometries, considering aspect ratios of order 1 and different lengths of the homogeneous inlet/outlet-flow regions. Micro-particle image velocimetry experiments were carried out in order to validate the flow kinematics, and the velocity profiles were found to be linear along the in- and outflow centrelines in good quantitative agreement with the numerical predictions.

Graphical abstract: Optimized cross-slot microdevices for homogeneous extension

Back to tab navigation

Supplementary files

Article information


Submitted
02 Dec 2013
Accepted
02 Jan 2014
First published
06 Jan 2014

RSC Adv., 2014,4, 7799-7804
Article type
Paper

Optimized cross-slot microdevices for homogeneous extension

F. J. Galindo-Rosales, M. S. N. Oliveira and M. A. Alves, RSC Adv., 2014, 4, 7799
DOI: 10.1039/C3RA47230B

Social activity

Search articles by author

Spotlight

Advertisements